Thanks for your support, all!
In the middle of this process I started thinking about my trackday pal who runs a mech workshop. I talked to him and supplied some simple drawings:
These beauties arrived - just what the doctor ordered:
So, now all I need is the most expensive nut in the world; the one that sits atop the supporting mount. I heard the guy at my local dealership say the magic words "Porsche Motorsports department" and knew it would take plenty time and money toi get them...